Tried to make a simple little “webapp” that converts Md2 models(the old quake 2 model format) into the json format(version 3) that is used by three.js.

You simply open the page, and then drag and drop a *.md2 file and it will be converted and a preview of the mesh should appear. You can then drag and drop jpg/png images for the texture to be previewed as well.
Left click and drag to rotate, right click and drag to move. Scrollwheel to zoom.
If it looks ok, enter a filename and hit “Save”.
It should now be downloaded(in Chrome at least, Firefox opens it in a new window).

You can then load in the json files into your three.js projects and use them as morphTargets.

I have only tested this in Chrome and Firefox, so not sure if it works anywhere else. Mostly done as an exercise for myself to understand the format, drag and drop and filehandling etc. But might be useful to someone else out there.

Edit (Mar 08, 2012): Looks like I had the exporter output a horizontally flipped model, should be fixed now. Thanks to @alteredq for letting me know.

Edit (May 11 2013): Updated it to export to the latest format(3.1).

Edit (Feb 10 2014): Fixed it, was broken due to some webgl changes in recent browsers.